Producing extractive materials from living trees



Sept. 30, 1952 A. B. ANDERSON 2,612,000

PRODUCING EXTRACTIVE MATERIALS FROM LIVING TREES Filed Aug. 24, 1949INVENTOR. A'rZ'b Lu" 5. flndens'on Patented Sept. 30, 1952 OFFICEPRODUCING EXTRACTIVE MATERIALS FROM LIVING TREES Arthur B. Anderson,Portland, Oreg.

- Application August 24, 1949, Serial No. 112,082

13 Claims.

The present application is a continuation-inpart of my co-pendingapplication (now abandoned) Serial Number 677,925, filed June 19,

1946, for Process for Increasing Yield of Extractives in Living Treesand Recovery Thereof.

As used in the above patent application, and as used herein, the termsextractives and extractive materials denote those components of the treewhich may be separated by extraction of the wood with neutral organicsolvents. Hence they refer particularly to rosin (resin acids),turpentine, pine oil, fats, fatty acids, sterols, tannins, cycloses,carbohydrates and similar materials. They do not refer to the integralcomponents of the wood, 1. e. the cellulose, lignin, and hemicellulose.

In the processes of the prior art relating to the production of suchextractives as rosin and turpentine or oleoresin from southern pines,first an area of the bark near the ground on one side of the tree isshaved off, after which a shallow cut is made a few inches above theground andan apron or gutter is inserted. A cup is placed below thegutter to collect the oleoresin drippings. A shallow streak or openwound, about A inch deep into the sapwood, is placed above the gutterwith a heavy short instrument called a hack.

Oleoresin soon appearsin droplets on the surface of the streak, and asmore of the yellowish white gum collects, it flows slowly over thegutter or apron and into the cup. It is customary to repeat thiswounding process weekly by chipping anew inch wide streak, to insurecontinued flow of oleoresin. If this scarifying is not repeatedperiodically, the wound soon ceases to produce additional oleoresin.After repeated scarifying, the open face may become several feet inheight. The amount of extractives or resin beyond the scarified surfaceis usually normal in amount and the lumber manufactured from such a treelikewise is not affected. This process is more fully described by Gerry,Oleoresin Pro duction, U. S. Dept. Agriculture, Tech. Bull. No. 262, U.S. Government- Printing Oflice, Washington, 1931.

It also is known that the turpentine wound can be made to .produceoleoresin flow over a longer period of time, without rescarifying sofrequently, by spraying the open wound with chemicals, such as mineralacids or alkalies. Consequently, about the same total. yield ofoleoresin per season can be obtained from acid-treated streaks made attwo-week intervals as from untreated streaks made at weekly intervals.Neither the oleoresin nor the wood beyond the acid treated scarifiedsurface is affected. This process is more fully disclosed by Everard,"Modern Turpentining Practices, U. S. Dept. of Agriculture, Farmer'sBulletin No. 1984, U. S. Government Printing Office, Washington, 1947.

, Another method used in obtaining extractives such as wood rosin, pineoil, and turpentine from southern pines is the solvent extraction ofsouthern pine stumps and light wood. It is the practice of the woodrosin processing industries to allow the stump to remain in the ground 8to 10 years to permit the bark and the sapwood, which contains littleextract, to slough off, thus leaving the heartwood in which theextractives are more highly concentrated. (Humphrey, Ind. Eng. Chem. 35,1063, 1943.) The seasoned pine stump heartwood which remains containsfrom 22% to 30% by weight extractives. It is then processed for therecovery of its extractive content by suitable methods such as, forexample, removing the stump from the ground, reducing it to chips orsmall pieces, and extracting the chips with a suitable solvent for theseparation of the extractives from the wood.

However, in actual application, the foregoing process has numerousdisadvantages principal among which are the fact that the maximum yieldof extractives is not realized until the stump has been permitted toremain in the ground for from 8 to 10 years, and the fact that thestumps from immature trees contain essentially sapwood which does notcontain a sufficient amount of extractive materials to warrant theirprocessing. For these reasons, the recovery of extractives from southernpine stumps is a very selective process, time consuming, and limited inits application.

It therefore is a primary object of the present invention to provide amethod whereby extractive materials may be deposited in large amounts inselected areas of living trees.

It is another object of my invention to provide a method wherebyextractive materials may be deposited continuously over long periods oftime in selected areas of living trees.

Still a further object of my invention is the provision of a methodwhereby living trees may be caused to deposit extractive materials inselected areas continuously over a long period of time without attentionor efiort beyond the initial treatment of the tree.

Another important object of my invention is the provision of a, methodfor treating living trees whereby to cause them to deposit in selectedareas extractive materialshaving a proportion of valuable constituentssubstantially greater than that normally found in the extractivesproduced by th same trees.

It is another object of my invention to pro: vide a method for greatlyincreasin the extractive content of the sapwood portion of the stumps oftrees so that the entire stump including both the sapwood and theheartwood portions may profitably be processed for the recovery ofextractive materials.

It is another object of my invention to provide a method for utilizingcull trees of little value as lumber as commercial sources of extractivematerials.

Still another object of my invention is the provision of a method forgreatly increasing the extractive content of immature trees composedalmost entirely of sapwood in order that such trees may be utilizedprofitably as commercial sources of extractive materials.

The manner in which the foregoing and other objects of the presentinvention are accomplished will be apparent from the followingspecification and claims considered together with-the accompanyingdrawings wherein:

Figure 1 is a View in elevation partly in sec- I tion of a tree whichhas just been treated by the presently described method, prior to theextensive deposit of extractive materials;

Figure 2 is a view similar to that of Figure l, but showing the treeafter a period of time has elapsed and after extractive materials haveaccumulated about the wound;

Figure 3 is a sectional view along the line 3-3 of Figure 1; and

Figure 4 is a view in elevation, partly in sec tion, of a tree which hasbeen treated by a modification of the method of my invention.

Broadly stated, the method of my invention for stimulating theproduction of extractive materials by living trees and for causing thecontinuing deposit of such materials in selected areas of the treescomprises first inflicting a substantially closed wound in the sapwoodof the tree, the wound penetrating the sapwood substantially to theheartwood region, and then permittin the continuous accumulation of theextractive materials throughout the woody structure of the tree in theregion of the wound. When the tree is treated in this manner, theextractive materials seal the wound protecting it from the atmosphericenvironment, and accumulate in the sapwood above and below the wound inhigh concentration. The deposit of extractive materials is continuouswithout further treatment of the tree so that ultimately a concentrationof extractives many times that, i. e. from 20 to 40 times that. normallyfound in this region of the tree has been deposited. The area of thedeposit is extensive, involving sections of the tree as much as severalfeet above and below the wound, the total quantity of extractivesdeposited being very large.

This is in direct contrast to the method of treating a tree in theordinary turpentining operation. In the latter operation, a shallow openwound is made in the tree which extends only a slight distance into thesapwood. This causes the exudation of a relatively small amount ofextractive (oleoresin) which runs down the side of the tree and iscollected.

As pointed out above, the exudation is not continuing, but stops after afew days. It then is necessary to wound the tree again to renew theprocess. This results in the formation of a scarred area which extendsafter a period of time several feet along the trunk of the tree. It isto be noted particularly that by the ordinary turpentining operationthere is no change whatsoever occurring within the woody portion of thetree. The extractive content of the woody portion is not increased, butremains normal in every respect. (Kurth and Sherrard, Ind. Eng. Chem.24, 11794 1932); Skolnik and Snow, Paper Trade Journal 122, 126 (March21, 1946) A further distinguishing feature of the present invention isthat hereinabove noted of resulting in the production of extractivematerials having a substantially different content than that produced inthe ordinary turpentimng operation. The difference fortunately is in thedirection of increasing the content of the more valuable constituents ofthe extractive product. Thus, by the practice of the present method theresin acids (rosin) content of the extractive product may be increasedfrom a normal value of about 25% to a value of about 60%. Similarly thecontent of volatile materials (turpentine) may be increased from a usualvalue of about 1.5% to a value of about 11%. Since these two materialsare the ones of greatest value, this feature adds greatly to the valueof my method.

The trees to which the method of my invention may be applied include ingeneral those which produce extractive materials by their physiologicalprocesses, the most important being those of the genus Pinus, includingthe southern slash pine, the southern longleaf pine, Pinus Zambertiana,Pinus monticola, and the like. In practicing my method, as isillustrated particularly in-Figure 1 of the drawings, a substantiallyclosed wound 9 is made in the tree H), penetrating the bark II, andextending substantially through the sapwood l 2 to the heartwood (3. Thewound may be made at any selected spot in the tree, but preferably ismade in the stump region for reasons which will be developed more fullyhereinafter.

The nature of the wound is such that the woodsubstance is disturbed andseparated, but without leaving a substantial opening, so that thewounded area is not exposed to the atomsphere. Such a closed wound maybe formed, for example by means of a wedge or other sharp instrumentwhich will penetrate the wood without removing a large amount of thewood substance. Alternatively, the wound may be made by means of rods orother blunt instruments such as rifle bullets driven at high velocityinto the wood, or by thin saws or small drills which do not leave alarge opening in the wood. In all of the wounds of the foregoing types,the wood fibers although displaced temporarily by the woundinginstrument tend upon the removal of the latter to spring back topositions approximating their original positions, thereby closing offthe wound.

The wound may be continuous for a substantial distance or discontinuous,but in any event should penetrate the. sapwood a substantial distance,preferably to the heartwood. In this Way a large number of the resinducts are intercepted and a correspondingly large amount of mences atonce.

'merci'al applications.

made by means of a wedge for a distance equal to about one-quarter ofthe circumference of the tree and extending through the sapwood to theheartwood. If desired, a second such wound l4 may be made on theopposite side of the tree, thus wounding in all about one-half of thetotal circumference of the tree.

After the wound has been made in the-tree, the deposition of extractivematerialsi com- These materials are deposited below thereof for an areawhich may after a period of time extend forseveral feet on either sideof the wound; The rate at which the extractives accumulate obviously isdetermined by manyriactors -.including the tree. species; the extent andnature 'ofthe'wounding, the climatic conditions, :etc. However, in theusual case a 6 v logging operations'..: In this application, the

wounds are inflicted about the stump portion of the tree from sixmonthsto two years before felling of the tree. During this period, theexi-tractivesn build up, in substantial quantities in the stump; {Thetree then may be felled and the "trunlr'portion converted'into lumber orpulp as' -desired. The stump may be processed immediately for recoveryof the extractives, since' substantial quantities'of the latterhave-=been deposited in the sapwood: This is in direct con-, jtrast tothepresentprocedure practiced because in the region of the wound andabove and s'uflicient amount of extractives will have accumulated aftera period from three to eighteen months to warrant their commercialrecovery.

The effect of wounding the tree in the manner indicated above is toimpregnate the wood above and below the wound with extractive materials.These may be recovered from the wood by felling the tree and separatingfrom the rest of the tree the areas having a high concentration ofextractives. These areas then may be reduced to theform of small.pieces' and extracted with a suitable solvent; acetone or apetroleumbydrocarbon; for. example, in which the extractives aresoluble.

vI "have discovered further that-therate of deposit ofextractive:materials about a closed wound inflicted well intothe'sapwood of-:,a living tree maybe accelerated byqthe introductionintothev'wounded area of an irritating chemical reagent. .Such a reagent maybekselected jfrom 40% by weight sulfuric acid, and a dilute aqueoussolution of caustic soda.

In using the foregoing and other chemical: reagents for stimulating theproduction of -extractives by a tree (Figure 4), the tree l5"firs't iswounded by inflicting a substantially closed wound it through the bark[1 well into the l8, to or near the heartwood l.9.i The it slightlydownwardly toweight of extractive materials respectively were sapwoodwound preferably slopes of thedeficiency of, the normal sapwoodinex-Itractive materials, and comprising permitting the stump to stand intheground for a period of from eight to tenyears during "which "time theextractives deficient s'apwood 'rots away-Heating the extractiverichfheartwood. Hence not only is -thelong waiting 'period avoided, butthe total" quantity of extractives' obtainable-froma given stump is verylargely-increased because-tlie'sapwood also-maybe processed for theirrecovery.

Still another application comprises that in which cull trees valuelessasvsources of lumber orpulp wood maybeemployed as generators ofextractive materials. In this application the closed woundsare inflictedat suitable intervals up and down thetrunk o'f the tree aswell as inthestump region. After a suitable waiting period, the tree may be felledand the entire tree,

including both the trunk and; stump, processed for the recovery of itsextractive content.

Stilla further application; which is-closelyrelated to that setforthimmediately-above; --com prisesutilizing asso'urces of extractivematerials immature-trees composed almost entirely of' ;'sapwood andnormally having a relatively small content of extractive 'materials:Here;;again the tree may beyvounded byLmeansofbIQsed won placed. atintervals Y intboth. the/stump. and trunk. ofthetree.Alternatively,.,i-f the-QtrunkQisto be devoted to anotherpurposethewhamm be-wounded, in this mannerra After a flperiod of time; sumcientfor the; accumulationgofamubr stantialaquantity of. extractivea -has.;,-passedmthe treemay be felledand thew-.ounded areas-on the trunk orstump; ors'both,mayebetreated for recovery of the developed andaccumulated extractives. 1 V The method of the present invention and the'eifect of its practice on the production of extracinto the tree atpoints above the wound, the

holes communicating with...fihe wound in the sapwood area. The "selectedchemical reagent then may be introduced into these holes w'he'reuponi'tflows downwardly into' the wourii iioofw ing thes'urfaot: -of thelatterf ---Because or the inward inclination of the wound, the chemicalreagent is retained therein and exerts its stimulating effect for asubstantial period of time.

The presently described method for producing,

extractive materials has several important com from the stumps remainingafter --commerci-al- In the first-place, it may tive materials byliving' t'rees and on the constituentsj of such extractivesareillustrated by --the followingqexamples.

EXAMPLE 1 l :Two ponderosa pine trees, A and 'B, -ll llef wood of whichcontained 2.9% .andj1;8%-1.l y

wounded by driving a falling Wedge into the tree about-* six nches ntothe sapwoodi Thea-wmiridand vanalyzedat variouslevels above and belowthe wound. The amounts of extractives present as, indicated bytheanalyses of the borings are given in: Table Lathe amountsbeingexpressedjin percent by weight. v. H

'TabZeI z 1 TreeA' l IreeB I Timeelapsedaftcn Timeelapsedaiter takenfrom wounding (days) f Per'cent 'woundingldays) Percent Increase 7Increase 6 above wound. 2.9 18.0 520 1.8 17.4 865 3" above 2.0 20.0 1.4010 1.0 14.3 21.4 1,090 1" above.. 2.0 22.5 27.0 880 1.8 24.8 33.3 1,750 1below 2.0 39.8 47.1 1, 520 1.0- 32.0 43.0 2,300 3below 2.0 30.722.7[ 020 1.8 21.3 29.7 1, 550 0"be10w. 2.9 10.4- 570 1.3 23.5 1,200

. The extractive inaterial obtained from the EXAMPLE 3 trees then wasanalyzed to determine its composition, and the results compared withthose A 26 men dlametel' ponderosa P1116 tree was obtained by ananalysisof the normal sapwood wounded inches mits b se. Increment of theunstimulated area of the tree. The comborings revealed that it containedapprox ma parison is set forthin Table II; 50% by weight of heartwoodand 50% by weight Table" II Resin Volatiles Water- Acids (Turpen- Etherwater Fatty Esters U-nsapon tll'l (Rosin) e Insoluble Soluble Acidsifiable NormaLJ 24.8; 1,0; 1.0 0.0. 40.0 12.0 0.2 Stimulated... 57.0 I10.0 0.0 0.4 7. 1 11.2 12.1

EXAMPLE 2 of sapwood, containing 20% and 3% extractives,

respectively. A ton of this stumpwood, if processed, would yield about230 pounds of extractives. The tree was wounded by driving a fallingwedge into it, about 5 inches into the sapwood. The wedge wounding wascontinued, until there was a. 20 inch continuous incision across theface of the trunk. A similar wound was placed on the opposite side, thusincising about the circumference of the tree. One year later the treewasfelled. The stimulated sapwood area. of the stump averaged extractivesas compared to its'former extractive content of 3%.

This example illustrates the efiect of stimulating the extractiveproduction about a closed wound by the addition of chemical reagents.

Two ponderosa pine trees, Cand D, the sap-.- wood of which contained 1.5and 1.9% by weight extractives respectively, were wounded as set forthin Example 1. Increment holes were placed periodically above the lengthof the .0 wound, and an aqueous 40 solution of sulfuric acid was appliedthroughout the area of the closed wound by pouring the acid down theholes. The trees then-were permitted to stand t n Qf this stumpwood,including the ununattended for one year, samp of e Wood stimulatedheartwood'area, yielded about 365 about the-Wound being taken d analyzedat pounds extractives, as compared to the 230 the end' of six month andtwelve month periods. pounds which would have been obtained if the Theresults are given in Table III: stump had remained unwounded.

' Table In Tree 0 I a Tree D I, Timeelgipsedaiter Time elapsedafterSample taken nom wounding (days) Percent wounding (days) Percent 1Increase I Increase 9"above woun l 5 27.7 1, 740 1 9 21.0 1,000 0" above1 5 12 0 32.2 2,020 1 s 15.3 27.2 1,310 1" below 1 5 40 2 40.2 2, 980 10 30.3 41.3 2,070 6"below 1 5 2s 0 30.4 1, 920 1 9 23.0 25.3 1, 230 0"below 15 18.8 1,150 1 0 19.2 010 The extractive material obtained wasanalyzed 1 1 EXAMPLE 4 and its content compared with that of a sample rA t similar t t t in Example 1, was ofthe normal, unstimuated sapwoodofthe tree. wounded as above. However,. after the wound These results aregiven in Table IV: 1 was placed in the tree, inclined increment .bor-Table IV Res in Volatiles 'Water a Fm y Upsapon- ($931 1) 555 111 5 3 51118 1? Acuis tlfiable N0rma1: f 22.7 1. 1.7 9.3 38.1'- 10.3 10.0Stimulated 52.7 .15. 0.3 2.3 05.0 -13.5 0.4

ingsme're. placed -.every' six inches above the wound; .:'The bottoms:of. the. increment borings reached theseveredrsurface. of the. closedwound about 3 inches into the sapwood. Forty per-cent .sulfuric;.acidwaspoured into each of these holes. Ten months lat'enpthe tree-wasfelled andthis stumpwood yielded approximately 460 pounds of extractivesper ton,: or twice. .as much as was present-in thestump prior towounding.

' EXAMPLE 5 A ten inchdiameter immature ponderosa pine tree consistinglargely of sapwood containing 4.5%.. extractive: was .woundednear; itsbase. Slightly inclined-;incrementborings, inch in diameter andabout 3inches-deemwere placed in the sapwood. until 40% .of thetotalicircumference of the tree-was wounded. Forty .per centsulfuric-acid was poured directly intothe slightly incliningincrementboringholes; Shortly thereaften most'of the-holes became-closedvwithextractives 3' The tree. was felled" 16 months later and theistump:area averaged 20.4% extractives, or about 5..times the:amountoriginallypresent.

Severalvpointed steel rods were-inserted well intothe sapwood of aponderosa pine tree, and then :removed. .=Eight een months later thetree was felled-and the wood-about the wounded area was segregated fromthe unstimulated areas I The stimulated pitchy area contained.-34.2-%vextractivesywhile. the-unaffected .or normal wood area contained .I5.5,%of these .materials. Thus the stimulated wood yielded over 'Gtimestheamount of extractivesfound' in the normal. wood.

ITh'e approximate composition of the extractives'obtained from thestimulated and unstimulated areas of the-tree aregiven in Table V:

ging. -tractor.' Nine'months later the deeply bruised sapwood of thestump. contained 32.6% extractives, while the unaffected area containedonly 8.'7% extractives. v

Hence it will be apparentthat I have provided a, method for obtainingextractive materials from trees which hast-many advantages-,anddistinguishingieatures overthe methods previously practiced.- -In thefirst-place. there are obtained from the practice of my method verygreatly increased yields of extractive materials, the extractive contentof V the sapwood beingincreased by a much-as 39 times that present inthe unstimulated i sapwood. In "the second place, ,,theextractivematerials obtained by. my method have a substantiallyincreased; content of turpentine androsin, the constituents of primaryinterest, the amount of the former being increased about sixfoldQand theamount-of the latter being about doubled. .Thirdly, .my method resultsin the continuin'g production. of extractive materials by a living treeoveralon'g .period of time without any attention. whatsoever beyond the.preliminary treatment of'thetree. Finally, my method may be. applied toadvantage in a number ofcommercial situations including the productionof extractive materials 'from' stumps while eliminating the eighttotenyear Waiting period which heretoforehasbeen necessary before thestumps have been. harvested; the recovery of ext'ractives from ,-cull:trees having. no other commercial value;;;ancl.the production ofextractives from immature trees -c. mr 1osed principally of sapwoodwhich .normally .has waninsufiicient content of extractive materials-towarrant their processing .forextractive recovery.

Having now described my invention in preferred embodiments, I'claim:

1. The. method of producing extractive .ma-

Table V.

Resin. .Volatilesi Water- F tt i U v Acids. .(Turpen- Ether a er Esters(Rosin) tine) Insoluble Soluble Amds" I g Normalfll; .\?:a.--2s.4 1.211.5 -7.6 424i 11-1 7.6- stimula ion"-.. tar 17.0. 0.9 0.6 4.2 V as 10.6

EXAMPLE 7 t s mm livinstree 'wh ch comprises inflict.-

, woodlo ingeacrossthe-grain direction of thewood. asubstantiallyrclosed wound wherein the-,woodiis severedvand: the,severed wood. suriac'es; are in substantial contact with; each, other,-the wound penetrating a substantial distance .in the sapdepositio ofnextractive materials inthe region or t e wound... permittingithe.faccuinulationlor th efi extractive materials, and th'enlrecoveri-ng.the. accumulated extractivemateria1s. from the wood T25 "me f.nroducinglextractive ma.- terialsfrom-'selected'areas ofliving' treeswhich comprises inflicting acrossthe grain. direction. of

Table VI Resin j vVolatiles Water-. .W Fat; Acids Turpen- .Ether e y(Rosin) tine) Insoluble soluble Normal.-." 24.8 1. 6 1 9 9.9$timulatedg- 57.9. 10.9 o 0 0,4

EXAWLEQB 1 i il i l y ie es dswound wherein The stump area of aponderosa pine tree "was wounded bymeans of a bladeattachedto a the,wood isgsever d-:;an:the:severedwood sur;

loemwaare-in:substantialeontact.with each ether.

thetr'ee. thereby causing the, continuing ructure-in. which they h vebeendeposited;

tial period of time, comminuting the portions of the tree containing theaccumulated extractive materials, and solvent extracting the comminutedproduct for therecovery of its extractive content.

3. The method of recovering values from living immature trees composedsubstantially of sapwood normally having a low content of extractivematerials, which comprises inflicting across the grain direction of thewood a substantially closed wound wherein the wood is severed and thesevered wood surfaces are in substantial contact witheach other, theWound penetrating a substantial distance into the sapwood in the stumpportion of the tree, thereby causing the continuing deposition ofextractive materials in the wood about the wound, permitting theaccumulation of the extractive materials in the stump over apredetermined period of. time, felling the tree and utilizing the trunkportion for its wood content, and. recovering the accumulated extractivematerials from the stump.

4. The method of recovering values from, living immature trees composedsubstantially of sapwood normally having a low content of extractivematerials, which comprises inflicting across the grain direction of thewood a substantially closed wound wherein the wood is severed and thesevered wood surfacesare in substantial contact with eachother,-the-wound penetrating 'a' substantial distance into the sapwoodin the stump of the tree,thereby causing the continuing deposition ofextractive materials in the wood about the wound, permitting theaccumulation of the extractive materials in the stump over apredetermined period of time, felling the tree and utilizing the trunkportion for its wood content, reducing the stump to pieces, and sol---vent extracting the pieces for recovery-of their extractive content.

5. The method of utilizing cull trees valueless as lumber whichcomprises inflicting-across the grain". direction of' the woodaplurality of sub stantially closed wounds wherein the wood substance'issever'ed'and the severed wood surfaces are=in substantial contact witheach other,the wounds penetrating a substantial distance. into thesapwoodalongthe trunk of the livingtree', thereby inducing thecontinuing deposition of ext'ractive materials inthe' wood about thewounds,

permitting the accumulation of extractive materials in the trunk over apredetermined period of time, felling the tree, and recovering fromthetrunk itsaccumulated content of extractive materials. v Y x 6. Themethod of utilizing cull trees valueless as lumber which comprisesinflicting across the grain direction of the wood a plurality ofsubstantially closed wounds wherein the wood sub-rv stance is severedand the severed wood surfaces arein substantial contact with each other,the wounds penetrating a substantial distance into the sapwood along thetrunk of the living tree, thereby inducing the continuing deposition ofextractive materials in the woodabout the wounds, permittingtheaccumulation of extractive materials inthe trunk .over a predeterminedperiod 12 of time, felling the tree, reducing the trunk to small pieces,and solvent extracting the pieces for recovery of their content ofextractive materials. v

7. The method of recovering increased amounts of extractive materialsfrom-the stump of a tree which comprises inflicting a substantiallyclosed wound in the sapwood of the stump portion of the live tree apredetermined time prior to its felling, the wound penetrating thesapwood to the heartwood region, thereby causing the continuingdeposition of extractive materials in the normally extractive-deficientsapwood, felling the tree after substantial amounts of ex tractivematerials have accumulated in the stump sapwood, and recovering theextractive materials contained in the stump.

8. The method of recovering increased amounts of extractive materialsfrom the stump of a tree which comprises inflicting a substantiallyclosed wound in the sapwood of'the stump portion of the live tree apredetermined time prior to its telling, the wound penetrating thesapwood to the heartwood region, thereby causing the continuingdeposition of extractive materials in the normally extractive-deficientsapwood, felling the tree after substantial amounts of extractivematerials have accumulated in the stump sapwood, comminuting the stump,and'solventextr'acting the comminuted stump for-the recovery of itsextractive content.

9. The method of stimulating the production of extractive materials by aliving tree and of causing the continuing deposition of saidmaterials inselected areas of the tree which comprises infiicting across the grain'direction or the wood a substantiallyfclosed wound wherein the .wood issevered and thesevered wood surfaces are in substantial contact witheach other, the wound penetrating a substantial distance into thesapwood of the tree, introducing into the wound anextractive-stimulating chemical reagent; permitting the accumulation ofthe extractive materials throughout the wood in the re gion of the woundfor a predetermined time, and then recovering the accumulated extractivematerials from the areas inwhich they have been deposited.

10. The method of claim 9 inwhich the extractive-"stimulating chemicalreagent is an inorganic acid.

1-1. The method of'claim9 in which the extractive-stimulating chemicalreagent is sulfuric acid. c

12. The method of claim} in which th1e ,ex tractive-stimulating chemicalreagent is an inorganic base. 7 v I 13. The method of claim Bin whichtheje'xtractive-stimulating chemical reagent is caustic soda.

ARTHUR B. ANDERSON.

REFERENCES CITED The following references are of record in the file. ofthis patent:

UNITED STA ES PATENTS (Othefreferences on routwmgtagew Number OTHERREFERENCES Ind. Eng. Chem, vol. 24, No. 10, pp. 1179-1181,.

October 1932.

14 FOREIGN PATENTS Sci. Am., vol. 169, No. 5, Pp. 202-204, Novemt t1781' 1.943. i 53 Leaflet 83, More Turpentine U. S. Dept. Great BritainJune 19, 1936 1 5 Netherlands 15, 1925 5 Occasmnal Paper 106, The Use ofChemlcal Stimulants U. S. Dept. Agr., Forest Service, Southern ForestExpt. Sta., page 1, September 1, 1944.

